PICTURE this: it's a crisp Sunday morning and you're on your hands and knees crawling on all fours across the mud flats of a river estuary. The rotting vegetable smell is retching, the feel of the gloopy mud presented in various shades of brown makes your skin crawl and the need to control your nerves with the mud clinging to your body, trying to suck you under is paramount.

This was the Maldon Mud Race across the River Blackwater in Essex. I joined 180 other souls for what amounted to a crawl from Promenade Park, across the river along a route marked by flags to the saltings, then a short slog running parallel to the Promenade before a final exhausting shuttle back across the river bed to the finish.

Of course, the race took place at low tide although there was still a 30 metre stretch of waist-high water to be crossed. Fortunately, marshals in wet suits from the Chelmsford Sub Aqua Group were on hand to help.

In total, the race distance was around 450 metres and watched by more several thousand spectators crammed on the promenade wall it was a gruelling slog.

The race began in 1973 following a dare waged with the landlord of the Queen's Head pub in Maldon.The challenge to the landlord was that the regular wanted to enjoy a meal served on the River Blackwater saltings from the landlord while dressed in a dinner jacket. The challenge was accepted and completed.

The following year, a bar opened on the saltings when 20 locals made a mad dash across the River Blackwater, drank a pint of beer and dashed back. This was the start of the Maldon Mud Race, although in the following years so many people wanted to take part that there was a logjam on the saltings with people drinking their pint of beer.

So the alcoholic side of the race was scrapped and the mud race became a straightforward dash across and back.

The race continued from the Queen's Head until 1989 when the Maldon Mud Race ceased, but because of public demand it was revived in 1994 as part of the Maldon Carnival Association's calendar of events and run in conjunction with the Lions Club of Maldon.

So on Boxing Day, 1994, 52 people took part in the race which started and finished from its new venue in Promenade Park, with around 5,000 people watching from the shoreline. This event also raised more than £2,500 for local charities.

Though the race suffered a temporary blip between 1998 and 2000 when the Maldon Carnival committee decided to abandon the event because of safety concerns, though it has now been run throughout the new century by the Rotary Club of Maldon and the Lions Club and in recent years more than £100,000 has been raised for good causes in Essex.

For the 2007 staging of the race, it attracted a host of weird and wonderful costumes - several Santas, fairies, there was Spiderman, kilt-wearing Scots with ginger wigs, someone dressed up as a horse and his partner wearing a rider's outfit, a fella in a dinner jacket, some blokes wearing these inflatable Sumo outfits, and one lady even carried round a palm tree.

I chose to wear the top and bottoms from the Santa outfit I wore in Liverpool earlier this month. It was disposable. Also, for the first time in this running challenge I wore football boots which were heavily taped up to my ankles to prevent them from being sucked under.

Just before the start a guy stood next to me gave me the best possible advice: save your energy and don't try to walk through the mud, it will sap your strength - just crawl.

A mud-fight between competitors just before the start got everyone dirty and in the mood and then it was off. We waddled down to the river bed and across the icy cold water. The first task was to climb up the sloping river bed on the other side of this channel. It was so hard to get any momentum going. Everyone was scrambling, clinging onto each other for support, pushing each other up the slope.

Walking was futile. You had to get on all fours and crawl. The mud crept to the top of your arms, you had to lift your head out of the way for fear of getting a mouthful. The smell was awful, the mud was icy cold too. It was hard, it was exhausting, and it was slow progress.

I managed to get to the saltings, and found a solid piece of ground on which I could walk slowly, before plunging myself into the mud for the return crossing.

It wasn't frightening, but I wasn't comfortable stuck in the mud. My clothes were being weighted down by the mud. My trouser bottoms were slipping off and I had to pull them up to keep them on. We clambered down the slope into the water, managed to walk across the river bed, and with the huge crowds cheering us on, plus a battery of newspaper and TV cameras filming our progress, we pushed on for a final surge/crawl to the finish.

Sad as it was, but my mud-splattered watch recorded a time of 10 minutes 17 seconds for the distance. The winner was home a good couple of minutes ahead, while some of the other competitors would take another half hour to finish.

There were cold showers waiting for us outside the finish area. I stripped off to shorts and a t-shirt, throwing my Santa outfit, football boots and socks in a bin. I managed to get a second shower in the public changing rooms. The mud was clingy and horrible, as a sea of brown dirt ran across the changing room floor.

"Don't worry about it mate," said one guy. "It will take at least a couple of days for the smell to go! You'll be smelling the River Blackwater on New Year's Day!!"